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  <title>将 ISO-8859-1 编码的字符串转换为 UTF-8 编码</title>
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  <div id="layout-content"><div id="function.utf8-encode" class="refentry">
   <div class="refnamediv">
    <h1 class="refname">utf8_encode</h1>
    <p class="verinfo">(PHP 4, PHP 5, PHP 7)</p><p class="refpurpose"><span class="refname">utf8_encode</span> &mdash; <span class="dc-title">将 ISO-8859-1 编码的字符串转换为 UTF-8 编码</span></p>

   </div>
   <div class="refsect1 unknown-unknown-returnvalueu" id="refsect1-function.utf8-encode-unknown-unknown-returnvalueu">
    <h3 class="title">描述</h3>
    <div class="methodsynopsis dc-description">
     <span class="methodname"><strong>utf8_encode</strong></span>
      ( <span class="methodparam"><span class="type">string</span> <code class="parameter">$data</code></span>
     ) : <span class="type">string</span></div>

    <p class="para rdfs-comment">
     该函数将 <code class="parameter">data</code> 字符串转换为 <em>UTF-8</em> 编码，并返回编码后的字符串。<em>UTF-8</em> 是一种用于将<span class="glossterm">宽字符</span>值转换为字节流的 <acronym title="Unique, Universal, and Uniform character enCoding">Unicode</acronym> 的标准机制。<em>UTF-8</em> 对于纯 <abbr class="abbrev">ASCII</abbr> 字符来说是透明的，且是自同步的（也就是说这使得程序能够得知字符从字节流的何处开始），并可被普通字符串比较函数用以比较等操作。PHP 可将 <em>UTF-8</em> 编码为多达四个字节的字符，如：
     <table class="doctable table">
      <caption><strong>UTF-8 编码</strong></caption>
      
       <thead>
        <tr>
         <th>字节（bytes）</th>
         <th>位（bits）</th>
         <th>表 示</th>
        </tr>

       </thead>

       <tbody class="tbody">
        <tr>
         <td>1</td>
         <td>7</td>
         <td>0bbbbbbb</td>
        </tr>

        <tr>
         <td>2</td>
         <td>11</td>
         <td>110bbbbb 10bbbbbb</td>
        </tr>

        <tr>
         <td>3</td>
         <td>16</td>
         <td>1110bbbb 10bbbbbb 10bbbbbb</td>
        </tr>

        <tr>
         <td>4</td>
         <td>21</td>
         <td>11110bbb 10bbbbbb 10bbbbbb 10bbbbbb</td>
        </tr>

       </tbody>
      
     </table>

    </p>
    <p class="para">
     每个 <em>UTF-8</em> 表示一个能被用以储存字符数据的位。
    </p>
   </div>

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